DD277698A1 - PROCESS FOR PREPARING SUBSTITUTED (S) -1,3-DIOXOLAN-4-CARBOXYLIC ACID ESTERS FROM THE RACEMATES - Google Patents

Abstract

The invention relates to a process for preparing (S) -1,3-dioxolane-4-carboxylic acid esters of the general formula (I) in which R 1 is an alkyl, aryl or substituted benzyl radical and R 2 is a methylene or ethylene group, or a CR 3 R 4 Radical, wherein R 3 and R 4 may be identical or different hydrogen, alkyl or aryl or together may be a tetra- or pentamethylene bridge, which may be used as a universally usable chiral building block, in particular for natural product and pharmaceutical synthesis, for example steroids & c. Takayama, S. Yamada, M. Ohmori EP 45,524 (1982), C.A. 97 (1982) 39240; A. Furst, L. Labler, W. Meier EP 63.678 (1982), C.A. 98 (1982) 198607 !, b-blocker & cf. Chem. 43 (1978) 4876 !, or as intermediates for the production of cosmetics. H. Moeller DE 3.447.783 (1986), C.A. 105 (1986) 158625! are suitable. According to the invention, (S) -1,3-dioxolane-4-carboxylic acid esters of the general formula (ICH2CHCOOR1 OO () I R2 are represented with the meaning explained for R1 and R2 by using racemic 1,3-dioxolane-4-carboxylic acid esters with the aid of proteolytic enzymes is separated into its antipodes such that the (R) -1,3-Dioxolancarbonsaeureester is hydrolyzed and the compound of general formula () I can be isolated. Alkaline serine proteases from B. licheniformis 41 P (ZIMET 10911), subtilisin DY and thermostable serine proteases from Thermoactinomyces vulgaris (ZIMET 9512 or ZIMET 9515) can preferably be used as proteolytic enzymes.

Description

R * characteristic of the known prior art

It is known that onantiomerone pure (R) - or (S) -1,3-Dioxolancarbonsäureester of the general formula (+) - or (-) - l can be prepared by Doaiotierung and Kotolisiorung of (R) - or (S) -serine (E.Schrötter, A. Hauser, HJ Hamann, H. Schick, B. Schönecker J. Prakt. Chem., 328 (1986) 705; CM.LoI ;, JPWard, DAVan Dorp Chem., Phys. Lipids 88 [1976] 115 ; R.Dumont, K.PfaenderHelv.Chirn.Acta 66 (19831814; J. Oelschlaeger, G.Gercken Lipids 13 (19781557; G, Hirth, W. Willy HeIv. Chim. Acta 68 1198511863). Mannitol and its derivatives can also be converted to enantiomerically pure 1,3-dioxolane-4-carboxylic acids by CC cleavage (R.Dumont, H. Pfander HeIv. Chim. Acta 66 (1983) 814, J. Oolschlaoger, G.Gercken Lipids 13 (1978) 557, CA 89 (1978) 215681; JJ Baldwin, AW Raab, K. Mensler, BHArison, DE McClure J. Org. Chem. 43 (1978) 4876; G. Hirth, W. Willy HeIv. Chim. Acta 68 (1985) 1863.) Finally, it is known that the

enantiomerically pure compounds of the general formula (+) - or (-) - 1 can be prepared by oxidation of isopropylideneglycerol with potassium permanganate (Y. Kawakami, T. Asai, K. Umeyama, Y. Yamashita J. Org. Chem. 47 [1982] 3581 ). These methods are characterized by high enantioselectivity, but require optically pure precursors and sometimes toxic reagents such. B. lead tetraacetate.

Object of the invention

The aim of the invention is to develop a process for the enzymatic resolution of 1,3-dioxolane-4-carboxylic acid esters with a high enantiomeric unit and satisfactory chemical yields, in which no toxic auxiliaries and no optically active precursors are required.

Explanation of the essence of the invention

The invention has for its object to develop an enzymatic process for the preparation of (S) -1,3-dioxolane-4-carboxylic acid esters of the general formula (-) - lzu.

According to the invention, this object is achieved in that a racemic 1,3-dioxolane-4-carboxylic acid ester of the general formula (+/-) -!

1 %

0 O (+/- HN S

R =

in the R ^{1 is} an alkyl, aryl or substituted benzyl radical and R ^{2 is} a methylene or ethylene group, or a CR ³ R ⁴ radical, wherein R ³ and R ^{4 are} identical or different hydrogen, alkyl or aryl or together a tetra or pentamethylene bridge, with proteolytic enzymes, preferably proteases of microbial and animal origin, for example serine proteases, is resolved into its antipodes. As proteolytic enzymes, alkaline proteases from Bacillus licheniformis 41P (ZIMET 10911), Bacillus subtilis and Thermoactinomyces vulgaris (ZIMET 9512 or 9515), for example alkaline serine protease from B. lirheniformis 41 p, thermostable protease from Thermoactinomyces vulgaris or subtilisin DY, can be used. The inventive reaction proceeds in a buffer solution, preferably in a phosphate buffer, at pH values of 2 to 10, preferably from 6 to 7, optionally in the presence of an organic solvent and at temperatures of 0 to 90 ° C, preferably 25 to 35 ⁰ C, such that the (R) -1,3-dioxolane-4-carboxylic acid ester of the general formula (+) - l

CH ₃ S-CH-CGOR ¹ -

1 i

Cl 0, +,.

R ^{= i}

by the addition of bases, preferably alkali metal hydroxides, hydrolyzed and the (S) -1,3-dioxolane-4-carboxylic acid ester of the general formula (-) - l can be isolated. Surprisingly, it is possible to realize the non-feasible with porcine pancreatic lipase (an esterolytic enzyme) hydrolysis, using proteolytic enzymes in satisfactory chemical yields and high enantiomeric purity.

embodiments example 1

363 mg (0.0023 mol) of the racemic 1,3-dioxolane-4-carboxylic acid ester of the general formula (+/- JI (R '= CH ₃ ; R ² = CR ³ R ⁴ ; R ³ = R ⁴ = CH ₃ )) in 10 ml of phosphate buffer (C = 0.01 M; pH = 7.01). and incubated at 29 ⁰ C the reaction mixture 20mg alkaline serine protease from B. licheniformis 41 P (ZIMET 10911) are added in the form of a dialyzed ammonium sulfate precipitation During the. Reaction, the pH was kept constant at 7.2 ± 0.1 with a 0.5N sodium hydroxide solution After consumption of 60% of the sodium hydroxide necessary for the saponification of an ester group, the reaction was stopped, the reaction mixture was extracted 4 times with ethyl acetate Dried, concentrated and passed through a silica gel column 121 mg (83%) of (S) - (-) - 1,3-dioxolane-4-carboxylic acid methyl ester of general formula (-) - l (FV = CH ₃ , R ² = CR ³ R \ * P ³ = R ⁴ = CH ₃ ). [A] _D ²⁰ = -14.8 (C = 4.85, CHCl ₃ ), eo = 84.3%.

Example 2

1.05 g (0.0066 mol) of the racemic IS-dioxolane-1-carboxylic acid ester of the general formula (+/-) - 1 (R '= CH ₃ ; R ² = CR ³ R ⁴ ; R ³ = R ⁴ = CH ₃ ) be in 30ml phosphate buffer (C - 0.01 M; pH = 7.01) and incubated at 30 ⁰ C. To the crude mixture is added 15 mg of B. licheniformes 41P alkaline serine protease (ZIMET 10911) in the form of a dialyzed ammonium sulfate precipitate. During the reaction, the pH was kept constant at 7.1 + 0.1 with a 0.5 N sodium hydroxide solution. After consumption of 60% of the saponification necessary for the saponification of an ester group, the reaction was stopped, the reaction mixture extracted 4 times with ethyl acetate. The organic phase was over sodium sulfate

dried, concentrated and separated on a silica gel. There are 273 mg (65%) of (S) - (-) - 1,3-dioxolane-4-carboxylic acid methyl ester of the general formula (-) - l (R '= CH ₃ ; R ² = CR ^J R ⁴ ; R ³ = R ⁴ = CH ₃ ) isolated. [a) _D ²⁰ = -12.1 (C = 2.73, CHCl ₃ ), ee = 69.3%.

Example 3

364.4 mg (0.0023 mol) of the racemic i ^ -Dioxolan ^ carboxylic acid ester of the general formula (+/-) -! (R '= CH ₃ ; R ² = CR ³ R ⁴ ; R ³ = R ⁴ = CH ₃ ) are suspended in 30 ml of phosphate solution (C = 0.01 M, pH = 7.01) and at 33 ° C incubated. 113 mg of thermostable serine protease from Thormoactinomyces vulgaris (ZIMET 9512 or 9515) are added to the reaction mixture. During the reaction, the pH was kept constant at 7.1 + 0.1 with a 0.5 N sodium hydroxide solution. After consumption of 60% of the saponification necessary for the saponification of an ester group, the reaction was stopped, the reaction mixture extracted 4 times with ethyl acetate. The organic phase was dried over sodium sulfate, concentrated and separated on a silica gel. There were 69.5 mg (48%) of (S) - (-) - 1, S-dioxolane ^ -carboxylic acid methyl ester of the general formula (-) - l (R '= CH ₃ ; R ^ CR ³ R ⁴ ; R ³ = R ⁴ = CH ₃ ) isolated. [a] _D ²⁰ = -15.1 (C = 3.47, CHCl ₃ ), ee = 86.7%.

Example 4

357 mg (1.78 mmol) of the racemic 1,3-dioxolane-4-carboxylic acid ester of the general formula (+/-) - 1 (R '= methyl; R ² = cyclohexylidene) are dissolved in 8 ml of phosphate buffer (pH = 7.01; 0.01 (suspended, incubated at 33 ° C. and admixed with 9 mg of alkaline serine protease from B.licheniformes 41P (ZIMET 10911) in the form of a dialyzed ammonium sulfate precipitate During the reaction, the pH became 7.5 ± 0.5 with a After consumption of 60% of the sodium hydroxide solution necessary for the saponification of an ester group, the reaction was stopped, the reaction mixture was extracted 4 times with ethyl acetate, the organic phase was dried over sodium sulphate, concentrated and purified on a silica gel column 131.8 mg (65.4%) of the corresponding ester of the general formula (-) i. [a] o ²⁰ = -6.44 (C = 10.14, CHCl ₃ ), ee = 34%.

Example 5

1.11 g (0.007 mol) of the racemic 1,3-dioxolane-4-carboxylic acid ester of the general formula (+ / -) - 1 (R '= CH ₃ ; R ² = CR ³ R ⁴ ; R ³ = R ⁴ = CH ₃ ) are suspended in 8 ml of phosphate buffer (pH = 7.01, C = 0.01) and 3 ml of acetonitrile, incubated at 33 ° C. and precipitated with 15 mg of B.licheniformes 41P alkaline serine protease (ZIMET 10911) in the form of a dialyzed ammonium sulfate precipitate added. During the reaction, the pH was kept constant at 7.3 ± 0.1 with a 0.5N sodium hydroxide solution. After consumption of 60% of the saponification necessary for the saponification of an ester group, the reaction was stopped, the reaction mixture extracted 4 times with ethyl acetate. The organic phase was dried over sodium sulfate, concentrated and purified on a silica gel column. This gives 193 mg (44%) of the corresponding ester of the general formula (-) - I. (a) _D ²⁰ = -11.0 (C = 9.64, CHCl ₃ ), ee = 63%.

Claims (4)

1. A process for the preparation of (S) -1,3-dioxolane-4-carboxylic acid esters of the general formula (-) - l CHa-CH-COOR *
I 1 , -HR ^a in the R ^{1 is} an alkyl, aryl or substituted benzyl radical and R ^{2 is} a methylene or ethylene group, or a CR ³ R ⁴ radical, wherein R ³ and R ^{4 are} identical or different hydrogen, alkyl or aryl or together a tetra or pentamethylene bridge, characterized in that racemic 1,3-dioxolane-4-carboxylic acid ester of the general formula (+/-) - l CHa-CH-COOR *
I f 0 o (+/- H R * with the meaning explained for R ¹ , R ² , R ³ and R ⁴ with the aid of proteolytic enzymes enantioselectively separated into its antipodes such that the (R) -1,3-dioxolane-4-carboxylic acid ester with the addition of bases, preferably alkali metal hydroxides , is hydrolyzed and the compound of the general formula (-) - l according to the invention can be isolated. 2. Method naoh claim 1, characterized in that the reaction in a buffer solution at "a pH of 4-10, preferably from 7.0 to 7.5, optionally in the presence of an organic solvent, at a temperature of 20 to 90 ⁰ C, preferably at 25 to 35 ⁰ C is performed. 3. The method according to claim 1 and 2, characterized in that as proteolytic enzymes alkaline proteases from Bacillus licheniformis 41 P (ZIMET 10911), Bacillus subtilis and Thermoactinomyces vulgaris (ZIMET 9512 or 9515), for example, alkaline serine protease B. licheniformis 41 p, thermostable protease from Thermoactinomyces vulgaris or subtilisin DY, is used. 4. The method according to claim 1,2 and 3, characterized in that aliphatic C ₁ -C ₄ -AIkOhOIe, acetonitrile, dioxane, acetone, tetrahydrofuran, nitromethane or dimethylformamide are added to the buffer mixture as the organic solvent. Field of application of the invention The invention relates to a process for the preparation of (S) -1,3-dioxolane-4-carboxylic acid esters of the general formula (-) - in which R 'is an alkyl, aryl or substituted benzyl radical and R ^{2 is} a methylene or Ethylene group, or a CR ³ R ⁴ radical, wherein R ³ and R ^{4 are} identical or different hydrogen, alkyl or aryl or together may be tetra- or pentamethylene bridge, which is a universally usable chiral building block, in particular for natural and pharmaceutical synthesis for example, steroids (see H.Takayama, S. Yamada, M. Ohmori EP 45,524 [1082], CA. 97 [1982] 39240; A. Fürst, L. Labler, W. Meier EP 63.678 (1982), CA. 98 (1982) 198G07), β-blockers (see JJBaldwin, AWRaab, K.Mensler, BAKrison, DEMOCIURE J. Org. Chem (1978) 4876), or as intermediates for the production of cosmetics (see H. Moeller DE 3.447.783 (1986), CA 105 (1986) 158625). CH ₃₆ -CH-COOR ¹